Vacuum pumps & controllers for degassing

High-quality components for efficient inline vacuum degassing of fluids

For over 20 years, Biotech Fluidics have supplied the ZHCR^® (Zero Hysteresis – Constant Run) family of stepper motor driven vacuum pumps that provide unmatched performance for continuous membrane degassing of liquids. This is indeed the perfect type of pump for vacuum degassing of fluids containing organic solvents since it truly excels in vacuum stability, quietness, and long lifetime.

The ZHCR^® pumps have been specifically designed and developed for membrane vacuum degassing of HPLC mobile phases and other mixed aqueous and organic fluids. Employing a micro-stepping motor speed control strategy, permits the pump to run continuously, without using higher speed than required to maintain the vacuum level. In addition, a dual stage (DST) vacuum control system initially provides high motor speed to enable quick pull-down of the vacuum, while then automatically switching to a low motor speed to sustain a consistent vacuum level once the setpoint have been reached. At ordinary use, during steady state, the pump operates at a speed of 50-80 rpm, thereby providing an excellent basis for a long operational life. Furthermore, fluctuations in baseline due to vacuum hysteresis are eliminated by not having to repeatedly stop and start a single speed pump. This also greatly reduces wear and noise.

The low power consumption of the brushless stepper motor enables the ZHCR^® pumps to run quietly with very little generation of heat, while also being very adaptable in its power supply requirements. This low heat generation is especially appropriate for an environment where solvents vapours may be present. The vacuum flow path materials were chosen for their ruggedness and compatibility with exposure to organic solvent vapours. The need for any vent valve has been eliminated by the continuously purged head design and the built-in anti-backflow duckbill check valves. The pump will start into full vacuum, and vacuum will not be released in the event of a power loss. The entire pump assembly also has a very compact design.

The most modern variants of the ZHCR^® vacuum pumps have an integrated control board with compact vacuum sensor. These pumps are extremely neat and easy to incorporate into assemblies and OEM-solutions, and are also providing the lowest acoustic profile. This series of pumps include models 9000-1920 to -1923, -2082, -2083, -2090, and -2091.

The latest features of ZHCR^® vacuum pumps is to provide a variable vacuum setpoint that is calibrated against the liquid flow rate through the degassing chamber. This CPD (constant performance degassing) technology tunes the pump motor speed to an ideal rpm that is providing sufficient degassing while minimising solvent vapour loss through the degassing membrane. This ensures that the integrity and composition of the degassed liquid is preserved regardless of flow rate, while still ensuring that there is no risk of outgassing and bubble formation throughout the flow system.

Benefits

• High and consistent vacuum level
• Quiet stepper motor with ball bearing drive
• Long life expectancy due to low rpm
• Continuously purged two-stage PTFE diaphragm head
• Built-in anti-backflow check valves
• Inert vacuum flow path
• Compact size

Degasser vacuum pump selector list